Mainspring composed of nickel base alloys



United States MAINSPRING COMPOSED OF NICKEL BASE ALLOYS Reinhard Straumann, Waldenburg, Switzerland No Drawing. Application March 29, 1954, Serial No. 419,579

Claims priority, application Switzerland (t nary 28, 1.94

7 Claims. (Cl. 75171) The present invention relates to a new corrosion-re- A sistant, substantially non-magnetic highly elastic mainspring for watches.

Many kinds of alloys have already been proposed for use as springs in watches.

Thus U. S. Patent No. 2,072,489 is directed to a nickel iron alloy with a hardening addition of beryllium, for the springs of thermo-compensated oscillating systems, for example balance springs for clocks and watches, in which with a content of 25-40% of nickel and 0.52% of beryllium with a calculated quantity of alloying addition of at least one of the metals of the group consisting of molybdenum, chromium and tungsten amounting to a total content of 5l2%, 0.52% of titanium is also alloyed, with the object that in addition to the great hardness achieved and the low temperature coeflicient, the dependence of the latter and its secondary error on the fixing temperature is greatly reduced to the rate of 0.5-1 second for each degree centigrade variation of the fixing temperature. This alloy containing as main constituent iron is well suited for the production of hairsprings or balance springs, but-in view of the high iron content not at all suitable for main springs. In fact such an alloy may be used for hairsprings having a constant and very small thermoelastic coefficient ranging in the neighbourhood of zero. Also the modulus of elasticity of such alloys ranges between 18,000 and 20,000 kg./mm. Moreover, springs made from such an alloy are relatively soft and show a limit of elasticity of about 80 kg./mm. Nevertheless such alloys are Well suited for hairsprings, that is to say for springs which are not subjected to very strong strain.

In view of my experiences in the watch field and as a result of the many tests made over a period of many years with watch springs I have found thatin this art even slight changes in the constitution of an alloy may cause important changes in the physical properties.

I have also found that for the production of special alloy watch main springs requiring a very high modulus of elasticityit is necessary that the alloy used therefor does not contain more than 25% of iron and should also comprise calculated small amounts of both beryllium and titanium.

The main object is thus a corrosion-resistant, substantially non-magnetic highly elastic main spring for Watches constructed of an alloy of the following composition:

In addition such an alloy may contain small quantities of conventional additives.

2,805,945 Eatented Sept. 10, 1957 "ice Indeed, the percentage of the various elements which.

Example 1 i i Percent Nickel 59 Iron l5 Chromium 15 Molyb denum' i 7 Beryllium 0.75 Titanium '1 Example 2 Nickel 59 Iron 16 Chromium 15.6 Molybdenum 8 Beryllium 0.3 Titanium 0.8

Example 3 Nickel 59 Iron 15 Chromium l5 Tungsten 7 Beryllium 0.75 Titanium 1 Example 4 Nickel 59 iron 16 Chromium 15.6 Tungsten 8 Beryllium 0.3 Titanium 0.8

Example 5 Nickel 59 Iron 16 Chromium 16 Tungsten 4 Molybdenum 3 Beryllium 0,75 Titanium 1 Example 6 Nickel 56 Iron 24 Chromium 11 Tungsten 4 Molybdenum 4 Beryllium 0,01 Titanium 0,05

Example 7 Nickel 50 Iron 13 Chromium 21,2 Tungsten Molybdenum Beryllium 1,

Titanium Percent Example 17 Example 8 Percent 1 Nickel 65 Nlckel 51 Iront 10 Iron 17 Chromium 21 Chromium 17v 5 Tungsten 4 Tungsten Molybdenum t 7 2 Blary Beryllium 7 I v t I l 1 Titanium 0.5 Titaniumj v 70.8 7 Example 18 V Exar zzple 9 Nickel 65 1 Iron 16 Nickel 56.6 Chromium 10 Iron Tungsten 4.2 Chromium 21 Molybdenum 7 p 7 7 4.3 Tungsten 7 Beryllium 0.15 Mdlybdemlm 4 Titanium 0.3 Beryllium 0.6 Titanium t r 05 The percentages, in the preceding examples as Well as in the following explanations, are throughout percentages t 1 Example 10 by weight. Ni k l 56 The alloys set forth in the examples may also contain 1 7 1 small quantities of conventional deoxidizing agents and Ch i 2L3 working-up additions, such for example as silicon and/ or T t 2 manganese, the total amount of these deoxidizers con- M l bd 4 25 taining at least one of the metals selectedfrom the group B lli 01 consisting of manganese and silicon ranging between 1 Ti i ()3 and 2%, although lesser or greater amounts may if de- Exam lg 7117 7 7 sired be used. 7 p 7 7 7 7 Titanium-free alloys; are known, the composition of Nickel 51 which is otherwisethe same as or similar to that of the al- Iron 7 7 7 13 loys accordingttothe present invention, and it has hereto- Chromiu m V 7 22 fore been the opinion of the skilled in the art that hard- Tungsten v 4 ness, elasticity and resistance to corrosion of such known Molybdenum 6 alloys could not be exceeded. 7 7 Beryllium 0.9 On the other hand, iron-free high nickel-containing al- Titanium 7 7 1.5 loys, havingta small chromium and molybdenum content, 7 and also containing beryllium and titanium, are known Example 12 and these have been intended for use as springs. Nickel However, none of these known alloys fulfills all the IIOII 18 49 high requirements necessary, more especially, for mainchl'omium 21 springs of clock and watch mechanisms. Molybdellum 8 Tests carried out for example with alloysof the follow- Beryllium ing composition: Titanium I 7 V 1 An N 1 ti f I Example 13 45 O157(3.ir0:1OI1S1S ng o Nickel 15% chromium Iron 11 7% molybdenum Chromium 15 0.75% beryllium Molybdenum 7 5O Remainder essentially nickel together with small Beryllium 1 quantities of silicon and manganese, Tltamum on the one hand, and

it t sExamplenM 7 7 7 7 7 7 Alloy No. 2 consisting of: Nlckel 7 r V 55 i III1 7 7 15 15% chromium Chrommm 7% molybdenum Molybdenum 6 0.75 beryllium B.eryl.hum 1% titanium- 7 Tltamum 0 Remainder essentially nickel together with small .ExamplelS. V r quantities of silicon and manganese, NiCkel 56 on-the other hand, show that, while the two alloys have Iron 14 comparable hardness and rebound properties, i. e. ca- Chfomium 23 pacity to return to original state after being flexed, the Molybdenum l springiness in the case of alloy No. 2 is surprisingly yl u greater than that of alloy No. 1. Other alloys of more Titanium or less similar composition and which have heretofore Exa'mple 16 been proposed for the same purpose as the alloys of the c 7 7 ,7 7 77 7 present invention are even more inferior in this regard. Nickel Q;Q;; 7 7 51 The provision, according to the present invention, of Iron l Q lfl h 16 a content of beryllium and titanium in alloys of the type Chromium 20.5 here involved, thus constitutes a considerable step for- T-urigstefi Q; 10 ward in the art, the realized superiority being of especial Beryllium}; 0.9 importancewhenlthe alloys are used in mainsprings of Titanium 1.5 clocks and watches. 1 r

Having thus disclosed the invention, what is claimed is:

1. A corrosion-resistant, substantially nonmagnetic highly elastic mainspring for watches constructed of an alloy of the following composition:

59% nickel iron 15% chromium 7% molybdenum 0.75 beryllium 1% titanium and The remainder being at least one metal of the group consisting of manganese and silicon.

2. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for Watches constructed of an alloy of the following composition:

59% nickel 15% iron 15% chromium 7% tungsten 0.75 beryllium 1% titanium and The remainder being at least one metal of the group consisting of manganese and silicon.

3. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for watches constructed of an alloy of the following composition:

59% nickel 15% iron 12% chromium 5 to 10% of at least one metal of the group consisting of molybdenum and tungsten 0.75% beryllium 1% titanium and The remainder being at least one metal of the group consisting of manganese and silicon.

4. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for Watches constructed of an alloy of the following composition:

59% nickel 16% iron 15.6% chromium 8% tungsten 0.3% beryllium 0.8% titanium The remainder being at least one metal of the group consisting of manganese and silicon.

5. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for watches constructed of an alloy of the following composition:

59% nickel 16% iron 16% chromium 4% tungsten 3% molybdenum 0.75% beryllium 1% titanium and The remainder being at least one metal of the group consisting of manganese and silicon.

6. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for watches constructed of an alloy of the following composition:

56% nickel 16% iron 21.3% chromium 2% tungsten 4% molybdenum 0.2% beryllium 0.3% titanium The remainder being at least one metal of the group consisting of manganese and silicon.

7. A corrosion-resistant, substantially non-magnetic highly elastic mainspring for watches constructed of an alloy having the following composition:

-59% nickel 14-16% iron 1222.7% chromium 510% of at least one metal selected from the group consisting of molybdenum and tungsten 0.21.2% beryllium O.3-2% titanium The remainder being at least one metal of the group consisting of manganese and silicon, the total of Mn-l-Si being not in excess of 3%.

References Cited in the file of this patent UNITED STATES PATENTS 

7. A CORROSION-RESISTANT, SUBSTANTIALLY NON-MAGNETIC HIGHLY ELASTIC MAINSPRING FOR WATCHES CONSTRUCTED OF AN ALLOY HAVING THE FOLLOWNG COMPOSITION: 